Directly attached storage (DAS) is a digital data storage system that is directly attached to a computer system (e.g., a storage server) without a storage network in between. A typical DAS system includes one or more data storage devices (e.g., disks) connected directly to a computer through a host bus adapter (HBA). Between the computer and the adapter there is no network device (e.g., hub, switch, or router).
The use of DAS can be a cost effective measure for data storage. In cloud storage where data is stored in multiple networked storage servers, the use of DAS can significantly reduces storage costs.
When a failure occurs in a computer system that is directly connected to a DAS, the DAS often becomes inaccessible. Such failure may occur when the computer system fails to power on (despite being connected to a power source), or the operating system of the computer system fails to boot or otherwise becomes inactive. Without an active and functional operating system, the content of the DAS in the current systems is inaccessible.